Designed during the last days of the Eve Wars conflicts of AC 195, the OZ-00MS2B Tallgeese III is intended to be another personal mobile suit of OZ leader Treize Khushrenada. However, its advanced weaponry takes a while to develop, and the Tallgeese III isn't ready in time for the war's end. However, the completed Tallgeese III ends up in the care of the new Earth Sphere United Nation's Preventers agency, and it's later be used in combat by Zechs Merquise - former leader of White Fang and now a Preventer agent, codenamed "Wind." The Tallgeese III makes its first appearance during the Mariemaia Army's revolt on Christmas Eve in AC 196. With the power of the Tallgeese III, Zechs almost single-handedly destroys or holds off many of the Mariemaia Army's new MMS-01 Serpent units. The Tallgeese III is a major improvement over the previous OZ-00MS Tallgeese and OZ-00MS2 Tallgeese II designs. For close combat, the Tallgeese III mounts a large shield which contains a retractable heat rod similar to that previously used on Zechs' OZ-13MS Gundam Epyon. The traditional pair of beam sabers remain intact, though the addition of a pair of head-mounted vulcan guns for close-range defense is a minor improvement. The Tallgeese III's primary weapon is its mega cannon, which replaces the original Tallgeese's dobergun. The mega cannon is extremely powerful - almost as powerful as the XXXG-00W0 Wing Gundam Zero's twin buster rifle. Zechs uses the Tallgeese III's mega cannon to destroy the Mariemaia Army's MO-III asteroid base with one shot.